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The Felbamate nanosuspension formulation was prepared by using the anti-solvent precipitation and ultrasonic method. In this work the polymers like HPMC K4M, Poloxamer 188.Polyvinyl alcohol, Polyethylene Glycol 400, as anti-solvent acetone was used. total eight formulations were prepared by using different composition of the polymers based on the prepared formulations (F1 – F8) were evaluated for Drug content, Solubility determination, In vitro drug release study, ATR-FTIR spectroscopy, Particle size determination and poly dispersity index, Zeta potential determination and Morphology characterization by scanning electron microscopy. All the formulations were evaluated for drug content which was in the range 90.15 & to 98.95 %The solubility determination of all formulations in phosphate buffer pH 6.8 was found to be in the range of 0.0156 mg/ml to 0.0375 mg/ml. The results showed that the solubility of formulation was found to be higher in F1 (0.031 mg/ml) compared with other formulations. The solubility of all formulations improved (from insoluble to slightly soluble) compared to pure drug of Felbamate. The in vitro release was carried out for all formulations. The results showed that as the concentration of polymer was increased, the percentage drug release was decreased. Optimized formulations showed 98.69% and 96.49% drug release within 120 minutes, but pure drug released upto 22.46% only. The release rate kinetic data for the best as a F1 formulation showed that the formulation provided good linearity was observed with the zero order (R2 = 0.9), the zero-order kinetics explains the good release of the prepared nanosuspension over the period of 120 minutes. The data were fitted into the Korsmeyer-Peppas equation which showed good linearity and the slope of the Korsmeyer-Peppas plot (n= 0.969) were found to be more than 0.45 indicating the diffusion mechanism is Case II transport. [ABSTRACT FROM AUTHOR]

Background: Idiopathic or genetic epilepsy commonly affects dogs; affected dogs are often refractory to anti-seizure drug therapy. Felbamate is an anti-seizure drug with established pharmacokinetic and safety data for dogs, but little published evidence of efficacy for managing generalized seizures in this species. Aim: The purpose of this retrospective case series was to evaluate the clinical efficacy and tolerability of oral felbamate in 6 presumptive epileptic dogs experiencing generalized seizures. Methods: Medical records from 6 dogs with presumptive idiopathic/genetic epilepsy manifesting as generalized seizure activity, for which oral felbamate was used as an add-on treatment, were reviewed. The number of seizures recorded for the three-month period immediately before instituting felbamate was recorded for each dog. Short-term (3 months) and long-term (6 months or greater) seizure frequency post-felbamate therapy was recorded for each dog and compared with baseline. Results: Overall, dogs experienced a reduction (82%) in seizures after adding felbamate in the short-term, with 5/6 dogs (83%) classified as responders (50% or greater reduction in seizures) and 3/6 dogs (50%) attaining seizure-free status. Mean and median long-term follow-up times were 13 and 11 months, respectively (range: 6 to 23 months). Four of the 6 dogs (67%) remained drug responders at final follow-up, with an average seizure reduction of 98%, 2 of which remained seizure free at 8 and 21 months. Two dogs (33%) experienced increased seizure activity during long-term follow-up (12 and 23 months) and were considered non-responders. The non-responder dogs had an average long-term seizure reduction of 33%. No dog experienced any obvious adverse effects associated with felbamate administration. However, one dog not included in the analysis because of insufficient (

Background: Idiopathic or genetic epilepsy commonly affects dogs; affected dogs are often refractory to anti-seizure drug therapy. Felbamate is an anti-seizure drug with established pharmacokinetic and safety data for dogs, but little published evidence of efficacy for managing generalized seizures in this species. Aim: The purpose of this retrospective case series was to evaluate the clinical efficacy and tolerability of oral felbamate in six presumptive epileptic dogs experiencing generalized seizures. Methods: Medical records from six dogs with presumptive idiopathic/genetic epilepsy manifesting as generalized seizure activity, for which oral felbamate was used as an add-on treatment, were reviewed. The number of seizures recorded for the 3-month period immediately before instituting felbamate was recorded for each dog. Short-term (3 months) and long-term (6 months or greater) seizure frequency post-felbamate therapy was recorded for each dog and compared with baseline. Results: Overall, dogs experienced a reduction (82%) in seizures after adding felbamate in the short term, with 5/6 dogs (83%) classified as responders (50% or greater reduction in seizures) and 3/6 dogs (50%) attaining seizure-free status. Mean and median long-term follow-up times were 13 and 11 months, respectively (range: 6 to 23 months). Four of the 6 dogs (67%) remained drug responders at final follow-up, with an average seizure reduction of 98%, 2 of which remained seizure-free at 8 and 21 months. Two dogs (33%) experienced increased seizure activity during long-term follow-up (12 and 23 months) and were considered non-responders. The non-responder dogs had an average long-term seizure reduction of 33%. No dog experienced any obvious adverse effects associated with felbamate administration. However, one dog not included in the analysis because of insufficient (<3 month) post-felbamate follow-up, was weaned off felbamate because of suspected hepatotoxicity. Conclusion: Our small case series suggests that oral felbamate might show promise as an add-on drug for epileptic dogs experiencing generalized seizures resistant to drug therapy. These results warrant a more controlled, prospective investigation into felbamate as a therapeutic agent for canine epilepsy. [ABSTRACT FROM AUTHOR]

Introduction: Concerns regarding felbamate adverse effects restrict its widespread use in children with drug-resistant epilepsy. We aimed to examine the efficacy and safety of felbamate in those children and identify the ones who may benefit most from its use. Methods: We retrospectively reviewed the medical files of all patients who were treated with felbamate in a tertiary pediatric epilepsy clinic between 2009-2021. Drug efficacy was determined at the first 3 months of treatment and thereafter. Therapeutic response and adverse reactions were monitored throughout the course of treatment. Results: Our study included 75 children (age 8.9 ± 3.7 years), of whom 53 were treated with felbamate for seizures, 16 for electrical status epilepticus during sleep and 6 for both. The median follow-up time was 16 months (range 1-129 months). The most common cause for epilepsy was genetic (29%). The median number of previous anti-seizure medications was six [4-8]. A therapeutic response ≥50% was documented in 37 (51%) patients, and a complete response in 9 (12%). Nineteen patients (25%) sustained adverse reactions, including three cases of elevated liver enzymes and one case of neutropenia with normal bone marrow aspiration. In all cases, treatment could be continued. All children with intractable epilepsy following herpes encephalitis showed a response to felbamate. Conclusion: Felbamate is an efficacious and safe anti-seizure medication in the pediatric population. [ABSTRACT FROM AUTHOR]

Abstract Background The objective of the work carried out was to assess the toxicity of the degradation products (DPs) for the drug felbamate. Stress studies were performed in the condition specified in the international council of harmonization (ICH) guideline Q1A (R2). Results The drug degraded under the alkaline stress conditions to generate two degradation products (DPs). They were separated on a Phenomenex C8 column (250 mm × 4.6 mm, 5 µm); mobile phase composition was 10 mM ammonium formate (pH adjusted to 3.7 with formic acid) and acetonitrile (80:20, v/v); flow rate and wavelength for recording absorbance were 1.0 ml/min and 206 nm, respectively. The structures of the degradation products were characterized by LC–MS/MS analysis. Conclusion The drug was prone to hydrolysis in the presence of alkali. It was found to be stable under other stress conditions, viz., acidic, neutral, thermal, photolytic and oxidative. The structures of the impurities were characterized by LC–MS/MS. The drug and the DPs were screened through ADME and toxicity prediction software’s like pkCSM, Toxtree and OSIRIS property explorer. Felbamate was flagged for possible hepatotoxicity.

IntroductionConcerns regarding felbamate adverse effects restrict its widespread use in children with drug-resistant epilepsy. We aimed to examine the efficacy and safety of felbamate in those children and identify the ones who may benefit most from its use.MethodsWe retrospectively reviewed the medical files of all patients who were treated with felbamate in a tertiary pediatric epilepsy clinic between 2009–2021. Drug efficacy was determined at the first 3 months of treatment and thereafter. Therapeutic response and adverse reactions were monitored throughout the course of treatment.ResultsOur study included 75 children (age 8.9 ± 3.7 years), of whom 53 were treated with felbamate for seizures, 16 for electrical status epilepticus during sleep and 6 for both. The median follow-up time was 16 months (range 1–129 months). The most common cause for epilepsy was genetic (29%). The median number of previous anti-seizure medications was six [4–8]. A therapeutic response ≥50% was documented in 37 (51%) patients, and a complete response in 9 (12%). Nineteen patients (25%) sustained adverse reactions, including three cases of elevated liver enzymes and one case of neutropenia with normal bone marrow aspiration. In all cases, treatment could be continued. All children with intractable epilepsy following herpes encephalitis showed a response to felbamate.ConclusionFelbamate is an efficacious and safe anti-seizure medication in the pediatric population.

Felbamate (FBM) is an antiepileptic drug that has minimal toxicity in preclinical toxicological species but has a serious idiosyncratic drug toxicity (IDT) in humans. The formation of reactive metabolites is common among most drugs associated with IDT, and 2-phenylpropenal (2-PP) is believed to be the cause of IDT by FBM. It is important to consider the species difference in susceptibility to IDT between experimental animals and humans. In the present study, we used an in vitro and in vivo model system to reveal species difference in IDT of FBM. Human cytochrome P450 (CYP) and carboxylesterase (CES) expressing microsomes were used to clarify the isozymes involved in the metabolism of FBM. The remaining amount of FBM was significantly reduced in incubation with microsomes expressing human CYP2C8, 2C9, 2E1, and CES1c isozymes. Chimeric mice with humanized liver are expected to predict IDT in humans. Therefore, metabolite profiles in chimeric mice with humanized liver were investigated after administration of FBM. Metabolites after glutathione (GSH) conjugation of 2-phenylpropenal (2-PP), which is the reactive metabolite responsible for FBM-induced IDT, were detected in chimeric mice plasma and liver homogenate. Mass spectrometry imaging (MSI) visualizes distribution of FBM and endogenous GSH, and GSH levels in human hepatocyte were decreased after administration of FBM. In this study, we identified CYP and CES isozymes involved in the metabolism of FBM and confirmed reactive metabolite formation and subsequent decrease in GSH using humanized animal model. These results would provide useful information for the susceptibility to IDT between experimental animals and humans. [ABSTRACT FROM AUTHOR]

Purpose: To assess the short-term and long-term comparative efficacy and safety of ASMs for Lennox-Gastaut syndrome (LGS).Methods: Following a systematic literature search, randomized controlled trial (RCT) and open-label extension (OLE) studies on LGS comparing ASMs with placebo or other ASMs were included. ≥50% reduction in drop seizure frequency from baseline and occurrence of treatment-emergent adverse events (TEAEs) were the primary efficacy and safety outcomes. For short-term outcomes, a network meta-analysis (NMA) reporting odds ratio (OR) with 95% confidence intervals (CIs) and hierarchy of competing interventions [surface under the cumulative ranking curve(SUCRA)] was done. Long-term outcomes were reported as proportion with 95% CIs using the random-effects model.Results: Fifteen studies including 1263 participants with LGS (aged 2-54years) receiving any of six ASMs [cannabidiol (CBD), clobazam (CLB), felbamate (FLB), lamotrigine (LTG), rufinamide (RFM), topiramate (TPM)] or placebo were included. High-dose CLB (1.0 mg/kg/day; CLB_H) [OR: 4.9; 95% CI: 2.3-10.8] was significantly associated with ≥50% reduction in drop seizure frequency as compared with placebo, and achieved the highest-ranking probability (0.89) based on SUCRA values (although there was an overlap between confidence intervals of effect sizes of CLB, RFM and CBD), while high-dose CBD (20 mg/kg/day; CBD_H) [OR: 3.8; 95% CI:1.6-9.0] had significantly higher odds for occurrence of any TEAEs and had the highest-ranking probability (0.85). Furthermore, the long-term treatment with CLB [78%; 95% CI: 70-85%] was associated with a significantly higher proportion of patients with reduction in drop-seizures, and long-term use of CBD [96%; 95% CI: 95-98%] was associated with a higher frequency of TEAEs.Conclusion: The study findings suggest that CLB_H, CBD and RFM are the most efficacious and safest in terms of both short and long-term outcomes with CLB_H probably leading the hierarchy. Future head-to-head trials comparing these ASMs are needed. [ABSTRACT FROM AUTHOR]

Since 1955, several alkyl‐carbamates have been developed for the treatment of anxiety and epilepsy, including meprobamate, flupirtine, felbamate, retigabine, carisbamate, and cenobamate. They have each enjoyed varying levels of success as antiseizure drugs; however, they have all been plagued by the emergence of serious and sometimes life‐threatening adverse events. In this review, we compare and contrast their predominant molecular mechanisms of action, their antiseizure profile, and where possible, their clinical efficacy. The preclinical, clinical, and mechanistic profile of the prototypical γ‐aminobutyric acidergic (GABAergic) modulator phenobarbital is included for comparison. Like phenobarbital, all of the clinically approved alkyl‐carbamates share an ability to enhance inhibitory neurotransmission through modulation of the GABAA receptor, although the specific mechanism of interaction differs among the different drugs discussed. In addition, several alkyl‐carbamates have been shown to interact with voltage‐gated ion channels. Flupirtine and retigabine share an ability to activate K+ currents mediated by KCNQ (Kv7) K+ channels, and felbamate, carisbamate, and cenobamate have been shown to block Na+ channels. In contrast to other alkyl‐carbamates, cenobamate seems to be unique in its ability to preferentially attenuate the persistent rather than transient Na+ current. Results from recent randomized controlled clinical trials with cenobamate suggest that this newest antiseizure alkyl‐carbamate possesses a degree of efficacy not witnessed since felbamate was approved in 1993. Given that ceno‐bamate's mechanistic profile is unique among the alkyl‐carbamates, it is not clear whether this impressive efficacy reflects an as yet undescribed mechanism of action or whether it possesses a unique synergy between its actions at the GABAA receptor and on persistent Na+ currents. The high efficacy of cenobamate is, however, tempered by the risk of serious rash and low tolerability at higher doses, meaning that further safety studies and clinical experience are needed to determine the true clinical value of cenobamate. [ABSTRACT FROM AUTHOR]

Background: We aimed to characterize newer antiseizure medications (ASMs)-induced hepatotoxicity in children and identify signals of disproportionate reporting of hepatotoxicity-related adverse drug events (ADEs)., Research Design and Methods: Case reports reported to VigiBase were accessed using Empirica™ Signal software. To summarize characteristics of the retrieved cases, descriptive statistics were used. A disproportionality analysis was conducted using the Multi-item Gamma Poisson Shrinker algorithm, which calculates Empirical Bayesian Geometric Mean value and its lower and upper 95% confidence limits (EB05 and EB95, respectively). EB05 > 2, N  > 0 was considered a signal., Results: Based on 870 analyzed cases, a higher proportion of cases was reported in girls than in boys and in patients aged 2-11 years than in other age groups. Most cases were serious. In 25 cases, hepatotoxicity resulted in death. A high proportion of patients ( n  = 275, 31.61%) experienced hypersensitivity reactions, mostly due to lamotrigine. The disproportionality analysis yielded 17 signals concerning felbamate, lamotrigine, levetiracetam, oxcarbazepine, stiripentol, and topiramate. Four signals were for severe liver injury and concerned felbamate, lamotrigine, levetiracetam, and topiramate. Gender-biased reporting frequency was detected for four ASM-ADE combinations., Conclusion: Our results should serve to raise clinicians' awareness about the potential association between several newer ASMs and drug-induced liver injury in children.

OBJECTIVE: We aimed to compare immunological, histological and oxidative effects of antiepileptic agents; felbamate and levetiracetam on head trauma in rats. MATERIALS AND METHODS: In this study, 32 Sprague-Dawley genus male rats were used. A closed head trauma mechanism was constituted in order to perform head trauma in rats. Rats were divided into 4 groups, and each group had 8 rats. Following head trauma, Group 1 (Control); normal saline was administered, Group 2; levetiracetam 50 mg/kg was administered, Group 3; felbamate 100 mg/kg was administered, and Group 4; levetiracetam 50 mg/kg and felbamate 100 mg/kg were administered with a combination. Injections were administered intraperitoneally once a day for 20 days. The rats were decapitated at the end of the 20th day. Blood and tissue samples were collected and analyzed for biochemical, immunohistochemical and histological parameters. RESULTS: Serum cytokine levels in Group 2, 3 and 4 were lower when compared to the control group. In Group 4, in which combined therapy was performed, cytokine levels were found to be the lowest. In Groups 2 and 3, a significant decrease in vascular congestion, mononuclear cell infiltration, hemorrhage, and neural degeneration was noticed in the pia mater. In Group 2, a decrease in vascular congestion and Purkinje cell degeneration was obtained in the cerebellum. However, the best outcomes were determined in Group 4. CONCLUSIONS: We determined that levetiracetam and felbamate alone are useful with respect to immunological, oxidative and histological alterations. However, their utility is better when used in a combination. [ABSTRACT FROM AUTHOR]

Felbamate is an anticonvulsant used in the treatment of epilepsy. In this study, we investigated the antidepressant‐like actions of felbamate in mice. The effects of felbamate were first assessed using the forced swimming test (FST) and tail suspension test (TST), and then investigated in the chronic unpredictable mild stress (CUMS) and chronic social defeat stress (CSDS) models of depression. The changes in the hippocampal brain‐derived neurotrophic factor (BDNF) signaling cascade after chronic stress and felbamate treatment were also examined. It was found that felbamate exhibited antidepressant‐like activities in the FST and TST without affecting the locomotor activity of mice. Felbamate was also effective in both the CUMS and CSDS models of depression. Moreover, felbamate administration fully restored the decreased hippocampal BDNF signaling pathway in both the CUMS‐stressed and CSDS‐stressed mice. Collectively, felbamate has antidepressant‐like actions in mice involving the hippocampal BDNF system. [ABSTRACT FROM AUTHOR]

Felbamate, an antiepileptic drug is administered multiple times a day to obtain proper restorative action against seizures in childhood onset epilepsy (Lennox-Gastaut syndrome), which usually result in poor therapeutic efficacy because of fluctuating plasma levels and low patient compliance. Hence, controlled release hydroxypropyl methylcellulose matrix tablets of felbamate were formulated to overcome these drawbacks. The results of pre-formulation studies such as differential scanning calorimetry and Fourier-transform infrared spectroscopy showed compatibility of drug with the selected excipients. The formulation variables were optimized using D-optimal design, which can elucidate the effect of all variables simultaneously during formulation optimization. In vitro drug release at the end of 2, 8 and 20 h were taken as the response parameters for the optimization study by D-optimal design. The results enabled selection of the formulation with the desired drug release pattern approaching to zero order. The optimized batch was subjected to in vivo pharmacokinetic studies in rabbits, which showed extended release of drug up to 24 h. Thus, the felbamate controlled release tablets optimized by D-optimal design have potential to reduce the dose and dosing frequency, improve therapy and patient compliance. [ABSTRACT FROM AUTHOR]

Antiepileptic medications are the frontline treatment for seizure conditions but are not without cognitive side effects. Previously, our laboratory reported learning deficits in phenytoin-, carbamazepine-, and valproate-treated rats. In the present experiment, the effects of felbamate (FBM) have been compared to water-treated controls (controls) using the same instrumental training tasks employed here. Rats treated with FBM displayed a deficit in acquiring a tone-signaled avoidance response, relative to controls, but this was true only if they had no prior appetitive experience. Terminal avoidance behavior was equivalent to healthy controls. In contrast, the FBM-treated rats showed enhanced acquisition of the avoidance response relative to controls when given the benefit of prior experience in the appetitive condition. Relative to animals treated with phenytoin, carbamazepine, or valproate, FBM-treated rats showed the lowest overall pattern of deficits using these instrumental learning tasks. While FBM treatment has been severely restricted because of rather low risks of serious medical side effects, we suggest that the risks are not substantially higher than those shown to exist for phenytoin, carbamazepine, or valproate. As psychologists, we further suggest that negative cognitive deficits associated with these various drugs, along with their quality-of-life costs, are of relevance in the design of treatment strategies for individuals with seizure disorders. [ABSTRACT FROM AUTHOR]